I see a lot of pics with bikes on rear stands.  I was wondering if there's something I'm missing?  Is it better to have the bike on a rear stand vs stock stand?

I'm assuming by "stock stand" you mean kickstand.  Anyways,  the reason people have rear stands is because it makes it easier/possible to perform general maintenance such as lubing chain, cleaning wheel, replacing sprocket and wheel.  So in that sense its better.  Not a big deal just get one.

Plus, it's just an all-around better way to garage your bike. Much less of a chance of it getting knocked over, and you avoid a potential flat-spot on your rear tire if it's being stored for an extended period of time. Some people even say that it alleviates long-term stress on your engine case, but I find that a little extreme, as these bikes are designed to stay on their sidestands indefinitely.

-Get one. I bought a Woodcraft one a few months ago and it was a fantastic use of $150.